Breathing assistance apparatus

ABSTRACT

A patient interface that is comfortable for a user to wear is disclosed. The patient interface includes a forehead rest and cushion. In particular the cushion includes a deformable resilient member that when compressed creates a uniformly and gradually increasing force while evenly distributing the pressure on the forehead of the patient.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 13/360,227, filed Jan. 27, 2012, which is adivisional application of U.S. patent application Ser. No. 12/784,016,filed May 20, 2010 (issued on Feb. 28, 2012 as U.S. Pat. No. 8,122,887),which is a divisional application of U.S. patent application Ser. No.10/564,998 (issued on Jun. 15, 2010 as U.S. Pat. No. 7,735,487), whichreceived a 371 filing date of Jun. 6, 2006 and is a 371 filing ofPCT/NZ2004/000165, filed on Jul. 27, 2004. These applications claimpriority from New Zealand Application No. 527313, which was filed onJul. 30, 2003. All of these references are hereby incorporated byreference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to patient interfaces particularly though notsolely for use in delivering Continuous Positive Airways Pressure (CPAP)therapy to patients suffering from obstructive sleep apnoea (OSA). Inparticular the present invention relates to forehead rest pads onpatient interfaces.

2. Description of the Related Art

In the art of respiration devices, there are well known variety ofrespiratory masks which cover the nose and/or mouth of a human user inorder to provide a continuous seal around the nasal and/or oral areas ofthe face such that gas may be provided at positive pressure within themask for consumption by the user. The uses for such masks range fromhigh altitude breathing (i.e., aviation applications) to mining and firefighting applications, to various medical diagnostic and therapeuticapplications.

One requisite of such respiratory masks has been that they provide aneffective seal against the user's face to prevent leakage of the gasbeing supplied. Commonly, in prior mask configurations, a goodmask-to-face seal has been attained in many instances only withconsiderable discomfort for the user. This problem is most crucial inthose applications, especially medical applications, which require theuser to wear such a mask continuously for hours or perhaps even days. Insuch situations, the user will not tolerate the mask for long durationsand optimum therapeutic or diagnostic objectives thus will not beachieved, or will be achieved with great difficulty and considerableuser discomfort.

U.S. Pat. No. 5,243,971 and U.S. Pat. No. 6,112,746 are examples ofprior art attempts to improve the mask system. U.S. Pat. No. 5,570,689and PCT publication No. WO 00/78384, and U.S. Pat. No. 6,119,693 areexamples of attempts to improve the forehead rest.

SUMMARY OF THE INVENTION

It is an object of the present invention to attempt to provide a patientinterface which goes some way to overcoming the abovementioneddisadvantages in the prior art or which will at least provide theindustry with a useful choice.

Accordingly in a first aspect the present invention consists in a devicefor delivering a supply of gases to a user comprising:

a patient interface, in use in fluid communication with said supply ofgases,

a forehead rest engaging said interface including a deformable resilientmember configured to in use rest against the face of a patient, saiddeformable resilient member when compressed in use creating a uniformlyand gradually increasing force, while evenly distributing the pressureon the area of the forehead of said patient that contacts said resilientmember.

Preferably said deformable resilient member has a top surface and a baseconnected by two side walls, said side walls being thin and in use arecompressible.

Preferably said top surface is substantially thicker than said sidewalls.

Preferably said top surface includes additional support at its centre tolimit its collapse.

Preferably said side walls are capable of folding under compression.

Preferably said deformable resilient member is moulded from silicone.

Alternatively said deformable resilient member is extruded fromsilicone.

In a second aspect the present invention consists in a device fordelivering a supply of gases to a user comprising:

a patient interface, in use in fluid communication with said supply ofgases,

a forehead rest engaging said interface including a deformable resilientmember configured to in use rest against the face of a patient, saiddeformable resilient member being of a hollow conical shape where in useand under compression the top part of said hollow cone deforms or theside walls of said cone deform.

Preferably said deformable resilient member is moulded from silicone.

Alternatively said deformable resilient member is extruded fromsilicone.

In a third aspect the present invention consists in a device fordelivering a supply of gases to a user comprising:

a patient interface, in use in fluid communication with said supply ofgases,

a forehead rest engaging said interface, an adjustable deformableresilient member mounted on said forehead rest, said adjustabledeformable resilient member configured to in use rest against the faceof a patient, said resilient member is height adjustable such that saidpatient can adjust the distance between said forehead rest and the faceof said patient.

Preferably said adjustable deformable resilient member is at least oneadjustable strap attached and adjustable on said forehead rest.

Alternatively said adjustable deformable resilient member is a memberrotatably mounted on said forehead rest.

In the alternate form the adjustable deformable resilient member beingrotatable relative to said forehead rest

In a further form said resilient member has two ends, one of theresilient member being fixed to the forehead rest, the other end of thestrap is free, said free end capable of sliding relative to saidforehead rest, said sliding of free end of strap allowing said user toadjust the height between said forehead rest and said forehead of saiduser.

Preferably said forehead rest includes a plurality of recesses, the freeend of the strap including a slideable sleeve, said slideable sleevesliding relative to said forehead rest and slideably moving said strapto adjust the height of said resilient member, said sleeve also capableof being fixed into any one of the recesses, said recesses allowingvarying degrees of height adjustment.

Preferably said forehead rest also including an aperture, said fixed endof strap fixed to said forehead rest by engaging into said aperture.

Preferably said strap includes a plurality of protrusions at each end,said protrusions at said fixed end of said strap engaging with saidaperture to fix said strap to said forehead rest, said protrusions atsaid free end of said strap engaging with said sleeve to connect saidstrap to said sliding sleeve.

Preferably said forehead rest is substantially T shaped, said foreheadrest comprising two lateral arms extending outward from a vertical arm,said resilient member attached to at least one lateral arm of saidforehead rest.

Alternatively said forehead rest is substantially I shaped.

In a further form said strap has a fixed end and a movable end, saidfixed end fixed to the forehead rest, said movable end is arranged onsaid forehead rest to form a substantially circular shape that providesa cushioning effect should a force be applied.

Preferably said movable end of said strap being threaded through anaperture in the arm to form said circular shape, said movable end ofsaid strap being adjustable on said forehead rest to allow a user toadjust the size of the circular shape created by said strap.

Preferably said strap includes a plurality of spaced apart apertures onthe strap, said forehead rest including a protrusion extending outwardfrom said forehead rest, said protrusion capable of engaging with anyone of said apertures on said strap to fix the movable end of said strapand fix the size of said circular shape, said plurality of spaced apartholes on strap allowing a user to adjust the size of said circularshape.

Preferably said forehead rest includes a holding sleeve, said holdingsleeve holding said strap in a substantially correct orientationrelative to the forehead rest and protrusion on said forehead rest.

Preferably said forehead rest is a substantially I shaped piece.

In another form said strap is arranged on said forehead rest to form twoarced sections relative to said forehead rest, said arced sectionsresting against a user's head and providing a cushioning effect.

Preferably said forehead rest includes at least one aperture, said strapcurled through said aperture to form a middle section extending in theopposing direction to said arced sections.

Preferably said strap is folded back on itself to form said middlesection, said strap having two ends, both ends of said strap fixed toopposing ends of said forehead rest.

Preferably said forehead rest includes a lip at each end of saidforehead rest, said rest comprising an abutment at each end of saidstrap, said abutment engaging with said lip to fix each end of saidstrap to said forehead rest.

Preferably said forehead rest includes a pair of apertures said strapcurling through both said apertures to form said middle section andarced sections.

Preferably said middle section can be pulled through or pushed throughsaid aperture or apertures in order to increase or decrease the size ofsaid arced sections.

Preferably said strap includes a plurality of spaced apart notches alongthe edge of said strap, said notches capable of engaging with saidaperture or apertures to hold said middle section in place, said notchesproviding incremental positions for the middle section to be held andsaid notches providing incremental sizes of said arced sections.

Preferably said strap has notches along both edges of said strap toprovide for better grip and engagement with said aperture or apertures.

BRIEF DESCRIPTION OF THE DRAWINGS

One preferred form of the present invention will now be described withreference to the accompanying drawings,

FIG. 1 is a block diagram of a humidified continuous positive airwaypressure (system) as might be used in conjunction with the presentinvention,

FIG. 2 is an illustration of the nasal mask in use according to thepreferred embodiment of the present invention,

FIG. 3 shows a perspective view of the mask with cushion,

FIG. 4 is a cutaway view of the mask showing the cushion,

FIG. 5 is a cutaway view of the periphery of the outer membrane,

FIG. 6 is a cutaway view of the periphery of the mask body portion,

FIG. 7 shows a prior art forehead rest in isolation,

FIG. 8 shows a section view of the prior art forehead rest of FIG. 7,

FIG. 9 shows a perspective view of the forehead rest cushion of FIG. 7,

FIG. 10 is a section of a further prior art forehead rest cushion,

FIG. 11 is a section of perspective view of the forehead rest cushion ofFIG. 10,

FIG. 12 is a back view showing the slots in the forehead rest for eachcushion to lock into,

FIG. 13 is a perspective view of a first embodiment of a forehead restcushion of the present invention,

FIG. 14 is a perspective view of a second embodiment of a forehead restcushion of the present invention,

FIG. 15 is an alternative perspective view of the forehead rest cushionof FIG. 14,

FIG. 16 is a section of the forehead rest cushion of FIG. 14,

FIG. 17 is a side view of a third embodiment of a forehead rest cushionof the present invention,

FIG. 18 is an alternative perspective view of the forehead rest cushionof FIG. 17,

FIG. 19 is a section view of the forehead rest cushion of FIG. 17,

FIG. 20 is a perspective view of a fourth embodiment of a forehead restcushion of the present invention,

FIG. 21 is a section of the forehead rest cushion of FIG. 20,

FIG. 22 is a perspective view of a fifth embodiment of a forehead restcushion of the present invention,

FIG. 23 is a sixth embodiment of a forehead rest cushion of the presentinvention,

FIG. 24 is a seventh embodiment of a forehead rest cushion of thepresent invention,

FIG. 25 is a perspective view of an eighth embodiment of a forehead restcushion of the present invention,

FIG. 26 is a perspective view of a ninth embodiment of a forehead restcushion of the present invention,

FIG. 27 is a perspective view of a tenth embodiment of a forehead restcushion of the present invention, where the forehead rest cushion isadjustable to a user's requirements,

FIG. 28 is a perspective view of an eleventh embodiment of a foreheadrest cushion of the present invention, this embodiment also beingincapable of being adjusted by the user,

FIG. 29 is a perspective view of a twelfth embodiment of the foreheadrest cushion of the present invention, where the forehead rest cushionis adjustable,

FIG. 30 is a perspective view of a thirteenth embodiment of a foreheadrest cushion of the present invention, this embodiment also beingadjustable,

FIG. 31 is a perspective view of a fourteenth embodiment of a foreheadrest cushion of the present invention,

FIG. 32 is a perspective view of a fifteenth embodiment of a foreheadrest cushion of the present invention, and

FIG. 33 is a perspective view of a sixteenth embodiment of a foreheadrest cushion of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides improvements in the delivery ofhumidified gases therapy. In particular a patient interface is describedwhich is more comfortable for the user to wear and reduces leakage ascompared with the prior art. It will be appreciated that the patientinterface as described in the preferred embodiment of the presentinvention can be used in respiratory care generally or with a ventilatorbut will now be described below with reference to use in a humidifiedCPAP system. It will also be appreciated that the present invention canbe applied to any form of patient interface including, but not limitedto, nasal masks, oral masks and mouthpieces.

With reference to FIG. 1 a humidified Continuous Positive AirwayPressure (CPAP) system is shown in which a patient 1 is receivinghumidified and pressurised gases through a patient interface 2 connectedto a humidified gases transportation pathway or inspiratory conduit 3.It should be understood that delivery systems could also be VPAP(Variable Positive Airway Pressure) and BiPAP (Bi-level Positive AirwayPressure) or numerous other forms of respiratory therapy. Inspiratoryconduit 3 is connected to the outlet 4 of a humidification chamber 5which contains a volume of water 6. Inspiratory conduit 3 may containheating means or heater wires (not shown) which heat the walls of theconduit to reduce condensation of humidified gases within the conduit.Humidification chamber 6 is preferably formed from a plastics materialand may have a highly heat conductive base (for example an aluminiumbase) which is in direct contact with a heater plate 7 of humidifier 8.Humidifier 8 is provided with control means or electronic controller 9which may comprise a microprocessor based controller executing computersoftware commands stored in associated memory.

Controller 9 receives input from sources such as user input means ordial 10 through which a user of the device may, for example, set apredetermined required value (preset value) of humidity or temperatureof the gases supplied to patient 1. The controller may also receiveinput from other sources, for example temperature and/or flow velocitysensors 11 and 12 through connector 13 and heater plate temperaturesensor 14. In response to the user set humidity or temperature valueinput via dial 10 and the other inputs, controller 9 determines when (orto what level) to energise heater plate 7 to heat the water 6 withinhumidification chamber 5. As the volume of water 6 within humidificationchamber 5 is heated, water vapour begins to fill the volume of thechamber above the water's surface and is passed out of thehumidification chamber 5 outlet 4 with the flow of gases (for exampleair) provided from a gases supply means or blower 15 which enters thechamber through inlet 16. Exhaled gases from the patient's mouth arepassed directly to ambient surroundings in FIG. 1.

Blower 15 is provided with variable pressure regulating means orvariable speed fan 21 which draws air or other gases through blowerinlet 17. The speed of variable speed fan 21 is controlled by electroniccontroller 18 (or alternatively the function of controller 18 couldcarried out by controller 9) in response to inputs from controller 9 anda user set predetermined required value (preset value) of pressure orfan speed via dial 19. Nasal Mask

According to a first embodiment of the present invention the patientinterface is shown in FIG. 2 as a mask. It will be appreciated thepatient interface could equally be a nasal mask, full face, oral mask ormouth piece, endotracheal tube or cannula by way of example. The maskincludes a hollow body 102 with an inlet 103 connected to theinspiratory conduit 3. The mask 2 is positioned around the nose of theuser 1 with the headgear 108 secured around the back of the head of thepatient 1. The restraining force from the headgear 108 on the hollowbody 102 and the forehead rest 106 ensures enough compressive force onthe mask cushion 104, to provide an effective seal against the patient'sface.

The hollow body 102 is constructed of a relatively inflexible materialfor example, polycarbonate plastic. Such a material would provide therequisite rigidity as well as being transparent and a relatively goodinsulator. The expiratory gases can be expelled through a valve (notshown) in the mask, a further expiratory conduit (not shown), or anyother such method as is known in the art.

Mask Cushion

Referring now to FIGS. 3 and 4 in particular, the mask cushion 1104 isprovided around the periphery of the nasal mask 1102 to provide aneffective seal onto the face of the user to prevent leakage. The maskcushion 1104 is shaped to approximately follow the contours of apatient's face. The mask cushion 1104 will deform when pressure isapplied by the headgear 1108 to adapt to the individual contours of anyparticular user. In particular, there is an indented section 1150intended to fit over the bridge of the user's nose as well as a lessindented section 1152 to seal around the section beneath the nose andabove the upper lip.

In FIG. 4 we see that the mask cushion 1104 is composed of a inner foamcushion 1110 covered by an outer sealing sheath 1112. The inner cushion1110 is constructed of a resilient material for example polyurethanefoam, to distribute the pressure evenly along the seal around the user'sface. The inner cushion 1110 is located around the outer periphery 1114of the open face 1116 of the hollow body 1102. Similarly the outersheath 1112 may be commonly attached at its base 1113 to the periphery1114 and loosely covers over the top of the inner cushion 1110.

In the preferred embodiment shown in FIGS. 3-6 the bottom of the innercushion 1110 fits into a generally triangular cavity 1154 in the hollowbody 1102. The cavity 1154 is formed from a flange 1156 running mid-wayaround the interior of the hollow body.

The outer sheath 1112 fits in place over the cushion 1110, holding it inplace. The sheath 1112 is secured by a snap-fit to the periphery 1114 ofthe hollow body. In FIGS. 5-6 the periphery 1114 is shown including anouter bead 1158. The sheath 1112 includes a matching bead 1159, wherebyonce stretched around the periphery, the two beads engage to hold thesheath in place.

Forehead Rest

A prior art nasal mask 102 including a forehead rest 106 is shown inFIGS. 2 and 7. The forehead rest 106 may move freely in proximity to themask body 102 and user, but with no lateral movement or may bepermanently fixed or adjustably fixed.

Referring to FIG. 7, at the top end 142 (around the user's forehead) ofthe bridge member 136 harnessing slots (not shown) are provided whichallow straps from the headgear to be inserted to secure the mask to theheadgear. For the user's comfort one or more resilient cushions 140 areprovided on the T-piece of the forehead rest 142 the top end of thebridge member 136, to rest on the forehead of the user. The cushion 140is constructed by injection moulding or extruding, from silicone or anyfoam materials as is known in the art for providing cushioning. In FIG.7 a second cushion 143 is shown at the other end of the section 142.

Forehead Rest Cushion

Referring now to FIGS. 8 and 9 the prior art forehead rest cushion 140is illustrated. The cushion 140, in cross section, includes an outercurved member 210 and a inner curved member 212 both of which areattached at each end to a straight base member 214. The inner curvedmember 212 is a substantially similar curved shape to the outer curvedmember 210. The inner member 212 and outer member 210 may becoterminous, the inner member may attach to the outer member 210 or bothmay attach to the base 214 separately.

When the cushion 140 comes into contact with the user's face the outercurved member 210 deforms as more pressure is applied to the cushiontowards the face. This comprises of the first mode of deformation. Oncethe outer curved member 210 deforms enough to contact the inner curvedmember a second mode of deformation occurs.

As will be appreciated if the outer curved member is flatter than thesecond curved member 212 the first mode requires less force. Therelative curvature and thickness of each can be varied to give acharacteristic first mode and second mode. Once in the second mode ofdeformation extra force is required to deform both the first curvedmember 210 and the second curved member 212. This configurationdescribed above results in more even deformation force across the loadbearing surface of the cushion 216 and also results in a moreprogressive force of cushioning when the cushion 120 is deformed.

A further prior art embodiment of a forehead rest cushion is shown inFIGS. 10 and 11. This forehead rest cushion 140 has an outer curvedmember 220 attached at either end to a straight base member 222. A innerinverted curved member 224 is inverted with respect the outer curvedmember 220 and is attached at either end two points on the 226, 228 onthe outer curved member 220. The inner inverted curved member is lowerin overall height than the outer curved member 220 such that a firstmode of deformation occurs when the outer curved member 220 is deformed.A second mode of deformation occurs when the inner inverted curvedmember 224 contacts the base member 222. The outer curved member 220 andthe inner inverted curved member 224 deform simultaneously. The forcesacross the load bearing surface 230 are further distributed by virtue ofa generally quadrilateral member 232 including as one side the basemember 222 which attaches over the inner inverted curved member 220approximately at its ends and at its load bearing point 234. Thequadrilateral member 232 provides additional stiffness and reduceslateral deformation.

These prior art forehead rests have a base member that includes a flange240 which engages with a slot 2138 in the forehead rest 106 to lock theforehead rest cushion in place. The flange 240 first slides throughaperture 2139 as seen in FIG. 12.

In the preferred forms of the forehead rest cushion of the presentinvention will now be described with reference to FIGS. 13 to 26, 31 and32. With each of the embodiments as described in relation to thesefigures the forehead rest cushion or pad allows for a controlledcompression of the cushion. Each cushion is capable of being compressedunder a force and will return to its original position (as shown in theFigures) when the force ceases.

A first embodiment of the forehead rest cushion is shown in FIG. 13.This forehead rest cushion 300 has a flange 301 that is able to beattached to a forehead rest, such as that rest 106 shown in FIG. 7 or12. The flange 301 slides through the aperture 2139 in the T-piece 2140of the forehead rest 106. The cushion 300 is substantially rectangularin shape with an upper wall 302 and lower wall 303, with the flangebeing attached to the lower wall 303. The side walls are corrugated orconcertinaed such that these walls 304, 305 collapse when a force isplaced on the upper wall 302. As described above, as the cushions aremade from a plastics material, such as silicone or foam, the foldsforming the side walls will return to the original form when anycompression force ceases.

FIG. 14 shows a second embodiment of a forehead rest cushion of thepresent invention. This forehead rest cushion 306 is a cushion that isin the general shape of a parabolic cone. The cushion has an open top307 that can be seen in FIG. 15, this open top 307 allows the edge 308of the cushion 306 to roll inwards when the top of the cone shapedcushion is compressed, or a force placed air on. This cushion may beattached to a forehead rest, such as the T-piece forehead rest as shownin FIGS. 7 and 12 by any appropriate means, for example, gluing or thelike and may include a flange such as that described above withreference to FIG. 13.

In alternative embodiments any of the forehead rest cushion of thepresent invention as shown in the Figures may have an alternativeattachment mechanism such as an arrow head type barb or protrusion,which fits into apertures on the forehead rest. Alternatively, any ofthe cushions may be provided with an aperture in place of the flangethat is able to be slid about an arm of the forehead rest.

A third embodiment of the forehead rest cushion of the present inventionis shown in FIGS. 17, 18 and 19. This cushion 309 has a conical body 310with a flattened circular top 311. This cushion is either injectionmoulded, extruded, or stamped from a sheet of material and is preferablymade of a thermoplastic elastomer, silicone or foam. Again, when a forceis applied to the top 311 the inner areas of the top roll inwards downtowards the top of the cone body 310. For example, as shown in FIG. 19in a section view when a force A is placed on the top 311 the inner areaof the top 311 moves downwards and the outer areas, shown as 311′, moveupwards or simply adjust to the shape of the area of user's forehead itabuts.

Reference is now made to FIGS. 20 and 21 where the force embodiment ofthe forehead rest cushion of the present invention is shown thisforehead rest cushion 312 is of a hemispherical shape and also allowsfor a two stage cushioning when a force is placed upon it. The cushion312 has a hemispherical body 313 suspended above a platform 314 and alsohas a flange 315 allowing the cushion 312 to be slotted into an aperturein a forehead rest, such as that described above. The hemispherical body313 is suspended above platform 314 on small supports 316, 317. Thiscushion 312 is preferably moulded from a thermoplastics material,silicone or foam.

A fifth embodiment of the forehead rest cushion is shown in FIG. 22. Thecushion 318 is shaped in the form of an “M” or generally rectangularwith a recess 319 formed in the top wall 320 of the cushion 318.Therefore, two inner vertical walls 321, 322 are formed parallel to theouter vertical walls 323, 324. When a force is applied to the upper wall320 the recessed part 319 and vertical walls 322, 321 are pusheddownwards towards the lower wall 325. When the apex 326 of the recessedpart 319 hits the lower wall 325 the cushion may still be compressed,but at a different rate of force such that the compression of thiscushion 318 is a two stage compression. The recess 319 in the middle ofthe cushion 318 therefore provides more uniform pressure across the topwall 320 of the cushion. As with other forms as described above thisforehead cushion 318 is supplied with a flange 327 attached to the lowerwall 325 allowing the cushion 318 to be attached to the forehead rest.

Reference is now made to FIG. 23 where a sixth embodiment of theforehead rest cushion of the present invention is shown. This cushion328 is of a similar form to that described in relation to FIG. 13, butits top or upper wall 329 is curved and the side walls 330, 331 merelyform one corrugation or fold. When a force is placed upon the upper wall329 the side walls 330, 331 fold in upon themselves. Again, this cushionhas a flange 332 attached to its lower wall 333 to allow the cushion 328to be attached to the forehead rest.

A seventh embodiment of the forehead rest cushion as shown in FIG. 24,this cushion is very similar in form to that of the prior art cushion asshown in FIG. 8 but its upper wall 335 is split in two and its innerwall 336 is horizontal in nature and not curved. Again, this cushion 334has a flange 337 that allows it to be attached to a forehead rest. Thiscushion provides a two stage compression where the inner wall providesstability to the cushion 334.

The eighth embodiment of the forehead rest cushion of the presentinvention is shown in FIG. 25. This cushion 318 has a base member 319having a flange similar to as described above in relation to the priorart cushions. The flange 340 allows the cushion 338 to be attached to aforehead rest. Two vertical walls 341, 342 extend upwards nearer thecentre of the base member 339, and a curved upper member in the shape ofa partial oval is attached above the vertical walls 341, 342. When aforce is placed on the curved upper member 343 the vertical walls 341,342 initially support the force placed on the upper member 343. Theouter edges 344, 345 of the upper member 343 are able to freely rollinwards to give further controlled support to the cushion 338.

A ninth embodiment of the forehead rest cushion of the present inventionis shown in FIG. 26. This cushion 346 has a base member 347 and a flangeattached to it to enable the cushion to be attached to a forehead rest.Extending outwards and upwards from the edges of the base member 347 arearms 349, 350. These arms 349, 350 are curved inwardly towards oneanother and may overlap. When a force is placed on the upper 350 arm,the arm 350 moves down towards the lower arm 349. If enough force or acontinued force is provided to the upper arm 350, the upper arm 350 willcontinue to compress against and push the lower arm 349 towards thecentre of the cushion 346 and the base member 347. These independentinwardly rolled arms 349, 350 allow for a two stage compression that iscontrolled when a force being placed on the upper arm 350.

A fourteenth embodiment forehead rest cushion of the present inventionis shown in FIG. 31. This cushion 351 has a similar shape to the priorart cushion of FIG. 9 and includes a base member 354 and a flange 353which engages with a slot 2138 in the forehead rest to lock the foreheadrest cushion in place. The flange 353 slides through and fixes in theaperture 2139 as seen in FIG. 12. The cushion 351 is substantiallyrectangular in shape but with an upper wall 352 that is slightly curvedat its edges where it meets the side walls 355, 356 of the cushion. Theupper wall is thicker in width than the side walls 355, 356 to provideadditional strength and control to the cushion. Furthermore, therelative thickness of the upper wall 352 compared to the side walls 355,356 prevents the cushion 351 from caving in. This helps provide auniform pressure on the user's forehead.

A further embodiment of a forehead rest cushion is shown in FIG. 32.This cushion 357 is exactly the same shape as that cushion of FIG. 31,but this cushion has an additional curved short wall 358 extending belowand following the contour of the upper wall 359. This short wall 358provides for additional support to the upper wall 359 when a force isplaced upon it.

FIGS. 27 to 30 and 33 illustrate forehead rest cushions that can beadjusted to a user's preference. Firstly referring to FIG. 27 a rotatingsubstantially circular or cam shaped cushion 360 rotatably mountablebetween two legs 361, 362, which are each attached and extend outwardsfrom the forehead rest or mask base, for example, one on either side ofthe T-piece as shown in FIG. 12. As the cushion 360 rotates in thedirection of Arrow B the offset is increased or decreased.

FIG. 28 shows a further embodiment of the cushion of FIG. 27. Thiscushion 363 additionally has a plurality of fixed attachments 364,similar to the flange on the cushions described above. Each of these canbe attached to the forehead support in turn to provide an adjustablecushion.

A twelfth embodiment of a forehead rest cushion of the present inventionis shown in FIG. 29. This cushion 365 is effectively a strap or flexibleelongate member (preferably made of a flexible plastics material)attached to one arm 366 of a T or to an I piece of a forehead rest. Inthe case of a T-shaped forehead rest, such as that shown in FIG. 12, twocushions of this type would be provided one for each of the two arms ofthe T-shaped forehead rest. The strap 365 is provided with a pair ofprotrusions 367, 368 at each of its ends 369, 370 such that a recess isformed between each set of protrusions. Each end 369, 370 is fixed tothe arm 366 by appropriate means, such as a sleeve 371 or aperture 372on the arm 366. In particular, the upper end 369 of the strap 365 isfixed to the arm 366 in the aperture 372 and the lower end 370 isslideably adjustable by way of a slideable sleeve 371 capable of slidingand being fixed into any one of a number of recesses 373 formed on theedge 374 of the arm 366.

A further embodiment of an adjustable forehead rest cushion is shown inFIG. 30. This adjustable cushion 375 is a strap or flexible elongatemember where a first end 376 of its two ends 376, 377 is fixed to an arm379 (similar to that arm 366 described above). The second end 377 of thetwo ends is threaded about and around such that a substantial part ofthe strap forms a circular shape that provides a cushioning effectshould a force be placed upon it. The second end 377 after beingthreaded through an aperture 381 in the arm 379, and possibly an furtherholding sleeve 380 formed on the arm 379, is fixed to the other side ofthe arm 379, for example by pressing a protrusion 382 through a hole 383formed in the strap 375. The size of the circular cushion formed can beadjusted as a plurality of spaced apart holes are provided in the strapand the strap can be pulled through the arm and the protrusion 382 fixedin each hole dependent on the requirements of the user.

Yet still a further embodiment of an adjustable forehead rest cushion isshown in FIG. 33, where a double loop strap 384 is formed into two arcedcushions 385, 386. Each of the apexes of the arced cushions 385, 386would in use rest against a user's forehead to provide additionalcomfort while wearing a mask or interface similar to that describedabove. The strap 384 has abutments 387, 388 formed at each end that fitunder lips 389, 390 formed in an arm 391 (such as, a one T-piece arm ofthe forehead rest as described above in relation to FIG. 12, or an Ishaped forehead rest as is known in the prior art and particularlydescribed in New Zealand patent application number 524439 of Fisher &Paykel Healthcare Limited). The middle section 392 of the strap 384 hasa plurality of notches 393 cut in each of its edges. The strap 384 isthreaded through two apertures formed in the middle of the arm 391, suchthat a substantial portion of the middle section 392 extends out fromthe arm 391 in an opposing direction to the arced cushions 385, 386. Themiddle section 393 can be pulled further through the arm or to pushedback through the apertures in the arm using the notches 393 asincremental positions for the middle section to be held in, to decreaseor increase the size of the arced cushions 385, 386.

The forehead rest cushion embodiments shown in FIGS. 27 to 30 and 33 areall user adjustable. In particular the forehead rest cushions shown inthese figures are height adjustable and allow the user to adjust theamount cushioning the forehead rest cushions can provide. The height ofthe forehead rest cushion is the distance between the forehead rest 106and the face or forehead of the user. The height adjustable foreheadrest cushion allows a user to adjust the distance between the foreheadrest and the lace of the patient. This allows a user to adjust theamount of cushioning provided by the forehead rest cushion.

In other forms of the forehead rest cushion of the present invention thecushion may be an inflatable member that can be manually inflated usinga syringe or a hand or finger operated compression pump, orautomatically inflated using a compressible reservoir or the like.

1. (canceled)
 2. A mask for a respiratory device configured to bepositioned around a nose of a user and secured around a back of a headof the user by headgear, the mask comprising: a hollow body providedwith an inlet configured to be connected to an inspiratory conduit; amask cushion provided around a periphery of the hollow body and shapedto follow contours of a face of the user to provide a seal configured toprevent leakage, wherein the mask cushion is configured to deform whenpressure is applied by the headgear to adapt to the contours of the faceof the user, and wherein the mask cushion includes an indented sectionintended to fit over a bridge of the nose of the user and a lessindented section to seal around an area beneath the nose and above anupper lip of the user, wherein the mask cushion includes an innercushion covered by an outer sealing cushion; and a forehead rest whichengages the hollow body, the forehead rest including two lateral armsextending outward from a vertical arm, wherein the forehead restincludes slots which allow straps from the headgear to be inserted tosecure the forehead rest to the headgear, wherein the two lateral armsof the forehead rest each include a resilient wall extending away fromthe vertical arm in order to rest on the face of the user, eachresilient wall extending away from the other resilient wall, and whereinthe resilient walls are configured to space the vertical arm of theforehead rest a distance from the face of the user, a recess beingdefined at least in part by the two resilient walls at a positionadjacent a top portion of the vertical arm of the forehead rest, betweenthe two resilient walls.
 3. A mask for a respiratory device configuredto be positioned around a nose of a user and secured around a back of ahead of the user by headgear, the mask comprising: a hollow bodyincluding an inlet configured to be connected to an inspiratory conduit;a mask cushion provided around a periphery of the hollow body to providea seal onto a face of the user to prevent leakage, wherein the maskcushion is shaped to follow contours of the face of the user, whereinthe mask cushion is configured to deform when pressure is applied by theheadgear to adapt to the contours of the face of the user, and whereinthe mask cushion includes an inner cushion covered by an outer seal,wherein the inner cushion is comprised of a resilient materialconfigured to distribute pressure evenly along the outer seal around theface of the user; and a forehead rest which engages the mask, theforehead rest including two lateral arms extending outward from avertical arm, wherein the forehead rest includes slots which allowstraps from the headgear to be inserted to secure the mask to theheadgear, and wherein the two lateral arms of the forehead rest spacethe forehead rest a distance from the face of the user.
 4. The mask ofclaim 3 further comprising headgear, wherein the headgear includes apair of upper forehead straps each of which is configured to extend overpart of the forehead of the user and is configured to be received inrespective slots on the forehead rest.
 5. The mask of claim 4 whereinthe headgear includes a pair of lower front straps located below theupper forehead straps and configured to extend over a portion of thecheeks of the user, the lower front straps configured to be secured tothe mask through a pair of lower slots, wherein the lower slots arelocated below the slots in the forehead rest.
 6. The mask of claim 5wherein the upper and lower front straps of the headgear extend from apair of junction members adjacent to the ears of the user.
 7. The maskof claim 4 wherein the headgear includes an upper rear strap which isconfigured to extend around an upper part of the head of the user. 8.The mask of claim 7 wherein the upper forehead straps and the upper rearstrap extend from a position above the ears of the user.
 9. The mask ofclaim 7 further including a lower rear strap located below the upperrear strap, wherein the lower rear strap is configured to extend arounda lower part of the rear of the head of the user.
 10. The mask of claim8 wherein the upper and lower rear straps of the headgear extend from apair of junction members adjacent to the ears of the user.
 11. The maskof claim 4 wherein the straps of the headgear each include a loop, theloop of each strap configured to be received in a respective slot on theforehead rest and/or the mask.
 12. The mask of claim 11 wherein theloops of one or more straps of the headgear are adjustable.
 13. The maskof claim 3 further comprising headgear provided with a pair of upperforward straps configured to connect to respective slots on the foreheadrest, and a pair of lower forward straps configured to connect torespective slots on the mask, the upper forward straps and the lowerforward straps located in front of the ears of the user.
 14. The mask ofclaim 3 wherein the mask cushion includes an indented section to fitover a bridge of the nose of the user, and a less indented section toseal around a region beneath the nose and above an upper lip of theuser.
 15. The mask of claim 3 wherein a cavity of the hollow body isgenerally triangular.
 16. The mask of claim 3 wherein the hollow bodyincludes an open face, the inner cushion being located around an outerperiphery of the open face of the hollow body, the outer seal beingcommonly attached at its base to the outer periphery of the open face ofthe hollow body, the outer seal loosely covering over a top of the innercushion.
 17. The mask of claim 3 including a mask shell which supportsthe inner cushion and the outer seal, the mask shell including a maskinlet configured to be connected to a breathing conduit.
 18. The mask ofclaim 17 wherein the mask cushion includes a plurality of bias flowholes through the mask shell.
 19. The mask of claim 3 wherein thelateral arms of the forehead rest are overmoulded onto the foreheadrest, the lateral arms of the forehead rest provided with at least oneslot through which the material of the overmould is received.
 20. Themask of claim 3 wherein the forehead rest includes a forehead restcushion of hemi-spherical shape, which allows for a two stage cushioningwhen a force is placed upon it.
 21. A mask for a respiratory deviceconfigured to be positioned around a nose of a user and secured around aback of a head of the user by headgear, the mask comprising: a hollowbody provided with an inlet configured to be connected to an inspiratoryconduit; a mask cushion provided around a periphery of the hollow bodyand shaped to follow the contours of a face of the user to provide aseal to prevent leakage, wherein the mask cushion is configured todeform when pressure is applied by the headgear to adapt to the contoursof the face of the user, wherein the mask cushion includes a sectionconfigured to fit over a bridge of a nose of the user and a section toseal around an area beneath the nose and above an upper lip of the user,and wherein the mask cushion includes an inner cushion covered by anouter sealing cushion; and a forehead rest which engages an interface,the forehead rest including a pair of laterally spaced slots which allowstraps from the headgear to be inserted to secure the mask to theheadgear at opposite sides of the forehead rest, wherein the foreheadrest further includes two arced sections, the arced sections restingagainst the head of the user and providing a cushioning effect, whereineach arced section includes an arm extending laterally from an upperportion of the forehead rest adjacent a longitudinal axis of theforehead rest, and wherein each arced section is spaced from theforehead rest by respective arms such that the arced sections space theforehead rest from the face of the user.